People often described Russell T. Davies' tenure as Doctor Who producer as reminiscent of a soap opera — but the show has become much more serialized, and more focused on a few core relationships, under Stephen Moffat. And Saturday's big season finale represents the culmination of a lot of Moffat's sweeping story arcs.

So how does it hold up? On the one hand, it's reminiscent of many of Moffat's best episodes — huge, jolly, audacious concepts and some utterly brilliant character moments. On the other hand, there are some bits of WTFery mixed in.

Here's our spoiler-free preview... And yes, that means absolutely no spoilers. Not even vague hints. Spoiler-phobes, be reassured!

For the most part, "The Wedding of River Song" is a lovely finale, as long as you don't think too much about some of the plot mechanics. There are many outstanding moments — and true to form, Moffat front-loads the thing with more ideas in the first 20 minutes than most writers fit into a dozen episodes. The Doctor has a few really powerful scenes, that will probably wind up being counted among the really great iconic moments, with any Doctor. Moffat's vision of what Doctor Who is about comes through strong and clear — but so does his love for all the other versions of the show that have aired, over the years.

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Another piece of good news: We get tons of answers, including answers to questions that you might have expected Moffat to keep you waiting until next year for answers to. And yet, in true form, those answers only spawn more questions, which will probably be keeping us guessing throughout 2012 and beyond. What's more, Moffat actually finds a way to raise the stakes — no small achievement, given how often the universe itself has been threatened lately.

Best of all, Moffat answers the thematic questions he's posed this year as well, about the Doctor's role as savior and warrior, and how he affects the people around him. And the thematic closure is mostly pretty satisfying — you wind up feeling as though this has been a pretty cohesive story, with a clear point to it. That's no small achievement, given how many television series finales fail to pass that test.

But is it a perfect episode? Well, no. It honestly depends how you felt about the last two Moffat "arc" episodes, "A Good Man Goes to War" and "Let's Kill Hitler." If you feel, as I do, that those two episodes had some serious flaws, then you'll notice the same flaws in "The Wedding of River Song." Once again, Moffat is trying to tell a huge, far-reaching story about the Doctor's complex relationships with Amy Pond and her daughter, River Song, and he takes some shortcuts along the way. Davies, for all his weaknesses as a storyteller, tended to take a lot more care in setting up character arcs that were far less ambitious.

But at the same time, Moffat plays fair with the main pieces of his storyline this time around, and the most important arc in the episode — the main storyline, about the Doctor facing up to his apparently immutable fate — is rock solid. Moffat has proved, again and again, that he is an inventive, manic creator who makes a constant stream of cool ideas and clever dialogue seem nearly effortless. But with this season's arc, he's managed to unite those strengths with a clear, consistent theme — and we're all better off for it.

If you've been holding off watching Doctor Who season six until you found out whether it had a satisfying ending, go ahead and watch the whole thing — in fact, BBC America has a handy marathon all day on Saturday. It does all pay off, mostly with greatness.